The invention relates to couplings, especially torque limiting couplings. The invention relates to the connection between a coupling housing and a connecting element. The connecting element connects a driving or driven component of a machine or an aggregate.
Couplings, especially torque limiting couplings, which act as overload couplings, are generally used to drive agricultural implements or self-propelled working machines. The couplings secure individual driven aggregates or component groups, as well as individual working tools against overload. When several couplings are arranged in a drive, and act to transmit torque to the driven branched working tools, a problem arises due to the working widths and the flexibility of the machine frame and the common driving shaft, in that the response behaviour of the coupling is negatively influenced in the case of an overload. Accordingly, sometimes no repetition accuracy to switch off is given, as restraints arise.
The invention provides a coupling, especially a torque limiting coupling, which ensures, independent of the arrangement in the driveline, a secure response with the necessary repetitive accuracy.
According to the invention, a coupling, especially a torque limiting coupling, comprises a tubular coupling housing defining a longitudinal axis. Starting from a first axial end, the coupling housing has a connecting bore portion. In a cross-sectional plane crossing the longitudinal axis at a right angle, the connecting bore has a circumferential inner contour. The contour is non-circular. The coupling housing has an insertion bore portion. An inner coupling member is accommodated in the insertion bore portion of the coupling housing. The inner coupling member is coaxially surrounded by the coupling housing. Torque transmitting elements are positioned between the coupling housing and the inner coupling member. Also, the torque transmitting elements cause rotational torque transmission between the coupling housing and the inner coupling member. A connecting element, which has a connecting portion, is accommodated in the connecting bore portion of the coupling housing. The connecting portion has an outer contour, in a cross-sectional plane crossing the longitudinal axis at a right angle, that follows the inner contour of the coupling housing at a radial distance. Thus, a clearance is formed between the two. Connection means connects the coupling housing to the connecting element. Accordingly, both are movably held relative to each other in a limited way.
An advantage of this embodiment is that the inner coupling member may move together with the housing relative to the connecting element. Thus, inaccuracies concerning the position of the inner coupling member and the outer coupling housing relative to the connecting element, can be absorbed. Accordingly, angular movements and/or axial movements and/or radial movements may be carried out with respect to each other. Thus, restraints are prevented. Likewise, the response behaviour of the coupling stays uninfluenced.
In an embodiment of the invention, the connection means enables a limited angular movement and/or axial movement and/or radial movement. The amount of movement is adapted to the application case. Angular, radial or longitudinal movement between the connecting element and the inner coupling member is only achieved by the insertion of the connecting portion, with clearance, in relation to the inner contour of the connecting bore portion of the coupling housing.
Preferably, the connection means are arranged in an area of the connecting bore portion of the coupling housing and the connecting portion of the connecting element. The connection means includes at least one opening in the coupling housing. Also, per each opening, a pin or a screw is insertable into an insertion bore of the connecting element. A splined pin is preferably used as the pin. Preferably, a hexagon socket head screw is used as the screw. The movability of the coupling housing to the connecting element, or the reverse, is achieved by the pin or screw engaging, with a clearance, the corresponding opening in the coupling housing.
Furthermore, the coupling housing over its total axial length has rib-like projections extending parallel to the longitudinal axis. The rib-like projections form grooves in the inner contour of the coupling housing. In this embodiment, the connecting bore portion and the insertion bore portion of the coupling housing are formed the same considering the clearance between the two. This is economical. The outer contour of the connecting element is formed in the area of the connecting portion of the inner contour following the coupling housing with rib-like projections. Partially cylindrical faces are formed between the rib-like projections. However, a clearance is provided. The pins or the screws are preferably provided in the area of the partial cylindrical faces.
From the following detailed description, taken in conjunction with the accompanying drawings and subjoined claims, other objects and advantages of the present invention will become apparent to those skilled in the art.